State health officials credit early planning and cooperation with hospitals and public health agencies for avoiding health-care worker resistance that other states are encountering.

More than 10 percent of the nation's emergency responders vaccinated against smallpox live or work in Missouri.

The Centers for Disease Control and Prevention reported last week that 1,043 people nationwide received the vaccine, including 119 in Missouri. Tennessee and Nebraska are the only states to report more vaccinations.

About 30 states have yet to administer the vaccine.

The effort is part of a nationwide plan announced in December by President Bush to vaccinate up to a half-million health care workers to serve on emergency response teams. The general public is not being vaccinated.

The teams would investigate and contain any initial outbreak of the highly contagious, deadly and disfiguring virus.

But CDC officials acknowledge that the response has been much less than expected.

Hospitals and labor unions are concerned that workers' compensation benefits won't cover health care and lost pay to those who suffer side effects from the vaccine, which may include fever and infections.

"This is just one of those situations where each hospital and person needs to make their own decision based on the best information available," said Becky Miller, vice president of the Missouri Hospital Association. "Fortunately, we've had a lot of people willing to step forward."

Missouri public health officials initially estimated they would vaccinate 5,000 health care workers. But screening for factors that might lead to an adverse reaction from the vaccine cut that number in half, said Pam Walker, director of the Center for Emergency Response and Terrorism in the Missouri Department of Health and Senior Services.

Vaccinations in Missouri began Feb. 7 and will continue through March. No serious adverse reactions have been reported.

Among those who received the vaccination are about 40 state health department employees, including the epidemiologists who would lead the field investigation of a smallpox outbreak and any vaccination effort to limit the spread of the virus.

The state also vaccinated public health nurses who would assist in mass vaccination clinics as well as police, Highway Patrol troopers and FBI agents.

Plans call for about 100 law enforcement officials to eventually be vaccinated.

"If there's a smallpox outbreak, that's an act of war, and we can't wait to begin an investigation," Walker said. "We want them with us from the first interview."